Hi Hilary, Thanks for this help.
It is being published to a remote SharePoint 2013 server.
Unfortunately I don't have a SharePoint administrator as such, the person who installs/maintains is pretty new to SharePoint, but have access to the server, can you tell me where to find the log files so I can view them, and try and work it out with the correlation id. Yes I am getting one with the error.
I didn't change the form load and about the only thing I remember doing is adding a people picker.
I have tried deleting the form from the site and starting from a fresh upload instead of replacing but no luck there either.
Could this be caused by permissions at all or by a data connection or only by faulty code in the form itself?
Jacqui.